1. Field of the Invention
This invention relates to lasers and, more particularly, to a solid-state laser whose laser medium is a single crystal of YGG:Cr.sup.3+ (Y.sub.3 Ga.sub.5 O.sub.12 :Cr.sup.3+)
2. Description of the Prior Art
A number of solids, both crystals and glasses, have been found to be suitable for laser action since the first (solid-state) laser was demonstrated by Maiman in 1960. Generally, the laser-active materials involve a rare earth, actinide, or transition metal dopant in a crystalline or glass host. An extensive treatment of then-known solid-state lasers was published in 1976-- Solid-State Laser Engineering, W. Koechner, Springer-Verlag, New York. More recently, a compilation of laser crystals was presented in Laser Crystals, A. A. Kaminskii, Springer-Verlag, New York (1981). YGG is among the garnet-structure crystalline laser materials tabulated by Kaminskii (p. 404). The activator ions disclosed are all rare earths--Nd.sup.3+, Ho.sup.3+, and Yb.sup.3+ (p. 451).
Laser action has also been demonstrated in GdScGa:Cr.sup.3+ garnet (A. Beimowski et al., XIIth Int'l. Quantum Electronics Conference, Munich, June, 1982) and alexandrite (BeAl.sub.2 O.sub.4 :Cr.sup.3+), a naturally occurring mineral having the chrysoberyl structure (U.S. Pat. No. 3,997,853). Among the distinctive features of the alexandrite laser is its tunability (U.S. Pat. No. 4,272,733).